Make a second UV layer for your model, unwrap for lightmap, bake lightmap, import into Torque, add your normal textures in the first material slot and in the second material slot, you just add the lightmap.

Make a second UV layer for your model, unwrap for lightmap, bake lightmap, import into Torque, add your normal textures in the first material slot and in the second material slot, you just add the lightmap.

If your model uses only one individual UV map, you can also bake the lightmap into the diffuse map with image editing program and save the additional material slot.
My described method is good, if you for example use tiling textures for the model, since then you can have tiling textures in the first UV map and the individual lightmap in the second UV map.